A CEM having an electron multiplication function includes a multiplication channel in which a secondary electron emission layer is provided, via a resistive layer, on an inner wall surface of a through-hole formed in a structural body or on a surface of defining a groove provided in the surface of the structural body. An input electrode is provided at an input end of the multiplication channel, and an output electrode set to have a potential higher than a set potential of the input electrode is provided at an output end of the multiplication channel. If charged particles taken from the input end reach a secondary electron emission surface, secondary electrons are emitted from the secondary electron emission surface. The emitted secondary electrons are multiplied in a cascade manner while propagating from the input electrode toward the output electrode.
The above-described CEM constitutes a CEM assembly along with a voltage supply circuit for applying a predetermined voltage between the input electrode and the output electrode, and the CEM assembly is applied to various sensing devices. As an example, the CEM assembly is combined with a structure (for example, electrode such as an anode) of collecting electrons emitted from the CEM, and thus may be applied to an electron multiplier device or the like which is widely used in the technical field of ion detection or the like.